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Electromagnetic Radiation
Electromagnetic (EM) radiation is the energy transmitted through space or a material medium in the form of electromagnetic waves. The frequency range of such waves is tremendous, and is shown by the electromagnetic spectrum. These waves include radio waves, microwaves, infrared waves, visible light waves, ultraviolet (UV) waves, X-rays, and gamma rays.
2,156 Questions
Where is visible light place in electromagnetic spectrum?
That's hard to discuss, because the electromagnetic spectrum has no ends.
If you name a frequency, then no matter how low it is, I can name a lower one,
and no matter how high it is, I can name a higher one. So, it's easy to describe
the size of the visible portion, but it's hard to describe the size of the full EM spectrum.
So let's just talk about the size of the part of the E&M spectrum that humans
use for radio communication, and ignore all the rest of it ... the infra-red, x-rays,
ultraviolet, gamma rays, all that other stuff. Only the part that we know how to
generate and modulate with very precise frequency control, and transmit and
receive over significant distances.
That's the portion of the E&M spectrum with frequencies from about 60 KHz
to about 100 GHz (wavelengths from about 3 millimeters to 5 kilometers).
'Linearly', that's a range of about 100 GHz bottom-to-top. But a much better
way to talk about parts of the E&M spectrum is logarithmically ... how many
'octaves' (doublings) or 'decades' (multiplied by 10) they cover.
Measured that way, our use of radio spans about 21 octaves, or about 6.2 decades.
Now we're ready to go look up the frequency/wavelength range of visible light.
A typical human eye will respond to wavelengths from about 390 to 750 nm
(3.9 to 7.5 x 10-4 millimeters). In terms of frequency, this corresponds to a band
in the vicinity of 400-770 THz (400,000 to 770,000 GHz).
That makes the visible range about 0.95 octave, or about 0.28 decade ... only
about 41/2% as wide as the range of wavelengths we use for radio communication!
Now, for fun, we'll try and include those other E&M phenomena that we've been ignoring.
We'll still have to decide where the ends of the spectrum are, because it really doesn't
have any.
For the bottom frequency, let's take 60 Hz. That's the small amount of RF that
radiates from power lines, which we always ignore. The wavelength is about
5,000 kilometers. (!)
Let's take gamma radiation for the top end ... the stuff generated in nuclear
decay, supernovas, black holes, that sort of thing. Dangerous stuff because
of its high energy. We're still here only because Earth's atmosphere absorbs
most of the gamma radiation from space, and not much of it ever reaches the
ground. Astronauts have to be shielded from it.
Gamma rays typically have frequencies above 10 exahertz (or >1019 Hz), and
wavelength less than 10 picometers (less than the diameter of an atom.)
So now, our 'expanded' range of electromagnetic spectrum covers 57.2 octaves,
or 17.2 decades, and the range of visible light is about 1.6% as wide as that.
Bottom line . . . we don't actually "see" a whole lot of the E&M spectrum, but
we know how to build instruments that detect the parts we can't see.
The sequence of the listing in the question is correct. From longest to shortest wavelength, these four categories of EM radiation do in fact list in the order: 1). infrared 2). visible 3). ultraviolet 4). X-rays
What electromagnetic radiation does the SOHO detect?
The Solar and Heliospheric Observatory (SOHO) detects various forms of electromagnetic radiation, including visible light, ultraviolet light, and X-rays. These different types of radiation provide valuable information about the Sun's activity and the solar wind.
Is there a connection between the speed of alpha beta and gamma radiation?
None whatsoever -- these three phenomena have almost nothing in common beyond (1) they all might come from radioactive material and (2) scientists of about 100 years knew so little about them that they simply named them the first three letters of the greek alphabet.
What substance in the earth's atmosphere absorbs a lot of the ultraviolet radiation from the sun?
Ozone is the substance in the Earth's atmosphere that absorbs a significant amount of ultraviolet radiation from the sun. It forms a protective layer in the stratosphere that shields the Earth's surface from harmful UV rays.
What is responsible for the absorption of ultraviolet radiation from the sun?
The ozone layer in the Earth's stratosphere is responsible for absorbing most of the ultraviolet (UV) radiation from the sun. Specifically, the ozone molecules absorb UV-B and UV-C radiation, protecting living organisms from the harmful effects of excessive UV exposure.
Radio waves, microwaves, and other parts of the electromagnetic spectrum differ in their frequency and wavelength. Radio waves have the lowest frequency and longest wavelength, while microwaves have a higher frequency and shorter wavelength. Other parts of the spectrum, such as infrared, visible light, ultraviolet, X-rays, and gamma rays, have progressively higher frequencies and shorter wavelengths. Each part of the spectrum interacts with matter in unique ways, influencing their applications in technology and communication.
Can gamma rays make a human being much powerful like the incredible HULK?
No, exposure to gamma rays will not give a person superhuman strength or turn them into the Hulk. In reality, exposure to gamma rays is extremely dangerous and can cause serious health issues such as radiation sickness, cancer, and even death. The Hulk is a fictional character created by Marvel Comics.
How is the suns energy transferred?
The sun transfer heat through radiation
Answer'Heat' is not transferred. Rather, 'heat' describes the process of transferring energy. So, your question should read, 'How does the sun transfer energy to earth?", and the answer is by radiation.
Alpha rays are not one of the waves of the electromagnetic spectrum. Alpha rays are actually streams of alpha particles, which are clusters of two protons and two neutrons emitted by certain types of radioactive materials.
Are x-rays energy the same as gamma rays?
X-rays and gamma rays are both forms of electromagnetic radiation, but they differ in their origin. X-rays are produced when high-speed electrons collide with a target, while gamma rays are emitted from the nucleus of an atom during radioactive decay. Both types of radiation have similar properties, such as high energy and ionizing capabilities, but they have different wavelengths and frequencies.
What does radiation poisoning do to people and animals?
Radiation poisoning occurs when individuals are exposed to high levels of ionizing radiation, leading to damage to cells, tissues, and DNA. Symptoms can include nausea, vomiting, hair loss, and in severe cases, organ failure and death. Both humans and animals can experience long-term health effects such as cancer and reproductive issues.
What gases in the atmosphere absorb infrared radiation and Which gases absorb ultraviolet?
Some of the gases found in our atmosphere which absorb infrared light are: carbon dioxide, methane, and water vapor. Gases found in our atmosphere which absorb ultraviolet light are ozone (O3) and oxygen gas (O2).
What is the difference between radiation protection and radiation safety?
Radiation protection focuses on minimizing exposure to radiation to prevent harm to individuals and the environment. Radiation safety, on the other hand, encompasses practices and measures put in place to ensure that radiation sources are properly handled, stored, and used in a safe manner to protect individuals and the public from potential harm.
What things has the highest frequency in the electromagnetic spectrum?
Visible light has the highest frequency in the electromagnetic spectrum. It falls between ultraviolet and infrared light, with a frequency range of approximately 430 to 750 terahertz (THz).
Can sound waves be polarized like electromagnetic waves can?
For polarization the direction of the oscillation has to be perpendicular to the direction of travel. In sound waves, which are longitudinal waves, this isn't the case and thereby can not be polarized.
What is the separation between hot spots in a 2.45 GHz microwave oven?
That's a very interesting question ... one that I've seriously been meaning to measure
for myself for a very long time but of course never quite got around to it.
The wavelength at 2.45 GHz is roughly 3 x 108/2.45 x 109 meters = 121/4 centimeters
(very round numbers).
Based on nothing but the seat of my finely tuned pants, I expect the spacing
of the RF standing waves in the cooking cavity to be related to that number,
and the structure of the hot spots to repeat with a period of either that or else
half of it. So before I set anything up, I would predict the separation to be
something close to either 4.8 inches or 2.4 inches.
Of course, now that you've asked and I've offered a blue-sky answer based on
nothing, I once again intend to measure it soon. I'll describe the method I plan,
but this is NOT recommended by anybody, least of all this website, and you did
NOT get this suggestion from any internet entity. (say that 5 times fast)
-- I'll make a sheet of ice, maybe a couple of inches thick, in a large disposable
aluminum pan in the freezer. With careful advance planning, I'll grease the pan,
and remove it after the freezing, leaving only the ice.
-- I'll take a sturdy, empty cardboard box of some kind, a few inches thick, stiff
enough to hold the weight of the ice, and small enough to fit into the MW. This
will get my test ice up off the bottom, where the standing-wave pattern may be
different from what it is out in the middle of the cavity.
-- I won't have to disable the turntable ('carousel') because ours hasn't worked
in months. But anyone else considering doing this experiment, in a controlled,
laboratory environment, with several OSHA, Fire Dept., and medical observers
present, which I am NOT suggesting that anyone consider doing, would want to
disable the turntable before proceeding.
-- I'll run the RF for maybe 15 - 20 seconds at a time, until I begin to see little
puddles developing on the surface of the ice. They may not all appear at the
same time, so it may take a few more shots to discern the overall pattern.
-- If a pattern does emerge, the spacing can be easily measured, after carefully
sliding the ice sheet out of the oven and immediately wiping up any spillage
before my wife comes in.
That's what I plan to do, but I am NOT recommending it for you.
What electromagnetic spectrum has the second longest wavelengths?
The electromagnetic spectrum that has the second longest wavelengths is the radio waves spectrum. They have frequencies ranging from about 30 kHz to 300 GHz, making them longer than microwaves and shorter than infrared waves.
Is cellphone radiation more harmful than just standing in bright sunshine?
No. Cell phone radiation is radio waves in the Megahertz and Gigahertz frequencies. This does not break up molecules in your body. Cell phone radiation is harmless. Solar radiation is infra red, visible light and ultraviolet light which can burn you and break up molecules on your skin, and also particle radiation which can break up molecules deep in your body.
What types of people use the ultraviolet radiation?
People who benefit from ultraviolet radiation include those with skin conditions like psoriasis who undergo UV therapy, individuals seeking to enhance their mood or treat seasonal affective disorder with light therapy, and those who use UV rays for sterilization purposes, such as in medical settings or for water treatment.
Do x ray and gamma ray telescopes have the same design as an optical instrument?
No, x-rays and gamma rays cannot be focused by lenses or conventional telescope mirrors. To make mirrors that will focus x-rays or gamma rays you need very shallow glancing angle mirrors, that are nearly just parabolically tapered tubes. Typically several of these tubes with the same focal point but different diameter are nested inside each other.
These are all forms of electromagnetic radiation, which travel in waves at different frequencies and wavelengths. They differ in energy levels and how they interact with matter. Electromagnetic spectrum ranges from radio waves with the lowest energy and longest wavelength to gamma rays with the highest energy and shortest wavelength.
From the items on that list, infrared light has the lowest frequency,
and X-rays have the highest.
What is the layer of the atmosphere in which the ozone absorbs ultraviolet solar radiation?
The ozone layer is located in the stratosphere, which is the second layer of the Earth's atmosphere. It absorbs and filters out a significant portion of the Sun's harmful ultraviolet (UV) radiation, protecting life on Earth from its harmful effects.
Is it true or false that electromagnetic radiation includes only visible light waves?
Actually, for most people, probably 98%, it is not possible to see UV light itself, you can only see the florescent effect resulting from UV light being reflected back as normal light by objects that have this property. The lens of the human eye filters out the actual UV spectrum in a normal human eye.
HOWEVER, some people have to undergo eye surgery to remove the lens (for various reasons) and once the lens is removed, those individuals (myself included) CAN actually see some of the UV spectrum.
Since I was a kid, I could not understand why "black lights" were called by that name, to me, they appear a very bright white-blue-violet color. They appear that way to me until I put my glasses on, because my glasses have a UV-blocking coating on them. As a result of my being able to see UV, when I am outdoors many colors have a more blueish-purple tint to them.
I am not sure how much of the UV spectrum people with my condition can actually see, but it is certainly very noticeable. So yes, SOME humans can view ultraviolet light.
